For the question 'if hurdle model is necessary', when you fit hurdle manually,
you will get two parameters, one from the count part, the other from 0 part. A
test of hypothesis parameter1=parameter2 then tests whether the hurdle is
needed or not.
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Renke Lühken wrote:
> The habitats are replicated, sorry for the confusion!
>
> How can I decide if I really need a zero-inflated model or is it just
> expert judgment?
> I decided that I need it, because more than 50% of the data are true
> zeros (detectability=100%) and therfore e.g. Martin et al
The habitats are replicated, sorry for the confusion!
How can I decide if I really need a zero-inflated model or is it just
expert judgment?
I decided that I need it, because more than 50% of the data are true
zeros (detectability=100%) and therfore e.g. Martin et al. (2005) or
Zuur et al., e
A few comments:
are the habitats replicated? If not, you have a fairly serious
experimental design problem -- you can't statistically distinguish
between the measured covariates and other, unmeasured/unintentional
differences among the habitats ...
* are you willing to treat complexity as a
Hi all,
I want to analyse an experiment at which insects were allowed to choose
between four habitats with different characteristics (see below). Number
of individuals per habitat were resampled six times (every 5 min). I
want to know which variables and which interactions of the variables
ha
